Rough cleaning and finish cleaning machine and method



THOD

2 Sheets-Sheet 1 INVENTORS A. H. FREEMAN ETAL ROUGH CLEANING AND FINISH CLEANING MACHINE AND ME 1962 Juli 16, 1963 Filed May 1l July 16, 1963 A. H. FREEMAN ETAL 3,097,450

ROUGH CLEANING AND FINISH CLEANING MACHINE AND METHOD Filed May 1l, 1962 2 Sheets-Sheet 2 INVENTORS A2055 H. FREEMAN Peeps/z /c KJ. Plc/14x20 mwm, A

A2' TORNEYS United States Patent O 3,097,450 ROUGH CLEANIN@ AND Fil-GSH CLEANING MACHNE ANB METHD Ardes I-I. Freeman, Granger, and Frederick J. Pichard,

South Bend, Ind., assiffnors to Bell Intercontinental Corporation, South Eend, Ind.

Filed May 11, 1962, Ser. No. 193,924 6 tiairns. (Cl. 51-13) This invention relates to machines and methods for cleaning up castings or the like; and more particularly to an improved machine system embodying yalternative bypass and cycling arrangements, `whereby `a single machine system may be eihciently employed to perform rsequentiially rough cleaning and finish cleanup processes on castings `or the like such as contain widely different debris and sand loads.

Previously, centrifugal blast type machines have not been found teasible for use in single process treatments of contain workpieces such as castings direct from the molds, because such machines do not operate eihciently under greatly varying sand and debris loads. The present invention, however, provides in la single blast machine system, means for selectively passing refuse and spent sholt through alternative cycling and temporary storage systems; whereby the blast machine component of Ithe system operates 'at all times yat the peak of its eiciency. More specifically, for example, the machine is more eiliciently operable to sequentially knock out the cores and otherwise roughclean the castings, and then 'to iinish-clean the castings without intermediate transfers `or other handling of the castings. Hence, the time loss and labor and capital expenses heretofore necessarily inherent to use of pri-or type machines and systems for such purposes are eliminated. Other objects and advantages of the invention will ybe apparent from the specication hereinafter, having reference to the accompanying :drawings wherein:

FIG. 1 is a somewhat `schematic elevational view with portions broken away to show interior details, of one form of machine system of the invention; and

FIG. 2 is a view similar to FIG. 1 Ibut of a modied system arrangement of the invention.

As shown in FIG. 1 `of the drawing, ia machine system of the invention may 4be constructed generally to comprise a workpiece support and carrying device such as a blast unit 1C including a cradle type conveyor 12 which supports and tumbles the load of cast-ings which are .to be processed, las indicated at 1S. A shot throwing machine as indicated 4at 16 is disposed above the load of castings and operates rto sling shot or other blast media against the workpieces at certain stages of the process as will be more fully explained hereinafter. The hopper and deed chute Afor supplying blast media to the unit 16 is indicated at 18, and the conveyor for carrying 'away spent media and debris is indicated at 2i).

With la view to simplilication of this specification the workpiece support and centrifugal blast machine components referred to will not be illustrated and described in further detail; the construction and operation of 'typical examples thereof being fully disclosed Iand explained respectively in U.S. Patents 2,104,055 :and 2,819,562. However, it is to be understood that in lieu of the specific form of workpiece supporting and tumbling and shot throwing devices illustrated herein and disclosed in the referenced patents, iany other suitable form of blast equipment may be employed; such as for example swing table machines `as disclosed in U.S. Patent No. 3,041,786.

In any case in accord with the present invention the blast machine 1d is coupled into a blast media and debris circulating and separation system which may include an elevator 22 shown as discharging the debris and abrasive 3,097,450 Patented July 16, 1963 mixture from the machine 10 through a cross conveyor 24 to a separator 28. The construction and operation of a separator of the preferred form is :illustrated yand described in full detail for example in my copending U.S. patent :application Ser. No. 831,525, led August 4, 1959. The separator includes a sand or refuse discharge yspout 29 delivering into any suitable take-away device as indicated at 30; and a reconditioned blast media discharge chute 32 delivering into the foot of a secondi elevator 34. Elevator 34 delivers tto ya cross conveyor 36 which has a primary delivery into another separator 37 which idelive-rs reconditioned shot to the hopper 18. Feeding of shot from the hopper 18 to the blast machine 16 is controlled by a valve 40. The separator 37 is of the type disclosed in detail in U.S. Patent 3,005,547, dated October 24, 1961. The conveyor 36 has a secondary delivery through ya control valve 42 to a storage or surge tank 44 ttor purposes which will now be explained; discharge from the bin 44 into the elevator 22 being controlled by a valve 46.

In operating the system of FIG. 1, when the castings to be processed have been stripped from their molds they `are loaded by ,any suitable means into the blast cabinet 10 of the machine; the valves 42, 46 being open. The door of the cabinet is then closed and if the castings contain `appreciable quantities of loose sand or other core or mold debris the castings may rst be :tumbled and/or turned for a predetermined time to cause the more easily displaced sand and core materials to fall out of the castings. During phase of the process the blast unit 16 may or may not remain idle, as preferred. In 'any case, the sand and debris falling from the workpieces into the conveyor 2d is passed rst `to the separator 28 from which much of the debris and non-reusable blast medita are discarded at 36. However, any sand and debris not removed during this rst pass through the separator 23 is automatically sent on through the elevator 34 and conveyor 36 and open valves `42 into the surge bin 44. From fthe surge *bin the mixture then ilows vat reduced rate back again to elevator 22 for repass through the separator 28 whereby further debris is removed until the system is substantially cleared by discharge of the waste material by the separator.

In the meantime the blast unit 16 is activated with valve 49 open. Hence, las the workpieces continue to be tumbled they are pelted with blast med-ia operating to clean up the workpieces Iby dislodging lfurther sand, scale, ctc. therefrom, las is well known in the art. When Ithe bulk of the initially dislodged surge of debris has been discarded rand/or absorbed by the surge bin, the valve 42 is closed and the mixture of spent blast: media 'and 4additionally dislodged debris is now carried 'by the conveyor yand elevator system first to the separator 28 and then to the separator 37 for normal separation 'and cleaning operation, rand so that the reconditioned blast media may `be again delivered to the hopper 18 and from thence recycled through the blast machine 16.

Throughout this phase of the operation, the valve 46 is controlled to permit only a reduced low rate therethrough, and as the amount of debris dislodged from .the work decreases, the separators 28, 37 catch up with the debris backlog and the percentage of debris in -the mixture being handled `by the separators `falls off rather sharply. Thus, the previously stored excess debris initially residing in the surge bin 44 is slowly drawn off through the valve 46, and is ied into the cleaning system, whereby it is eventually all transported through the separators 28, 37 and all waste materials rthereof eliminated.

By virtue of this machine arrangement the large initial surge loads of `sand and debris which occu-r when the cores are being dislodged from the castings are temporarily sidetracked to the surge bin, whereby flooding of the separain accord with the present invention through the separators and tors is avoided. Also, the flow of sand and abrasive their associated circulation system may be easily maintained at a substantially constant rate. This avoids the possibility of sand passing through the separators to the blast machine, and also prevents static accumulations of sand at various points in the system such as would otherwise result in stratification and periodic dumping (due to vibration) of harmful surges of sand into the system.

The system may of course be controlled in any preferred manner, such as fully automatically or manually, or semi-automatically. Typically, it may be effectively controlled (after empirical determinations of the most eiiicient arrangements of the operative sequences, accord- -ing to the conditions to be met) by means of a single programmed timer. Thus, by virtue `of the arrangement of the present machine system the separator components will be operating at all times at peak efficiency, and the blast machine unit lwill also be operating at peak efficiency, and without requiring it to handle any appreciable amounts of debris such as would be harmful to the machines as well as detrimental to the efficiency of the overall operation.

FIG. 2 discloses a modified form of the machine system arrangement such as requires substantially less floor space but more headroom, compared to the machine system arrangement of FIG. l. In this case, the operative components of the system are equivalents to the system arrangement of FIG. 1, and with a view to simplification of illustration and description, like components have been assigned like designating numerals. `It will be noted, however, that the arrangement of FIG. 2 requires the use of only one elevator which is designated 22 in lieu of the elevators 22-34 of FIG. l. In both cases the material from the blast cabinet l goes first to the separator 28 and then is directed toward separator 37 with a bypass conduit leading to temporary storage bin 44. Again, the discharge from storage bin 44 goes to the elevator feeding the separator 28. Therefore, it will be appreciated that the system of FIG. 2 may be controlled and operated so as to provide the same operative results as the system of FIG. 1; and it will be appreciated of course that although only two forms of the machine of the invention have been illustrated and described in detail hereinabove, it will be understood that various changes may be made therein without departing from the spirit of the invention or the scope of the following claims.

We claim:

1. A method for sequentially removing cores or the like and other lange volume debris from workpieces such as castings and then finish-cleaning the same, which method comprises placing a workpiece on a support arranged to tumble said workpiece for shaking out a surge load of core material or other loose debris while delivering the debris to a first separator, transporting the overload material from said first separator to a second separator while diverting a portion of the overload material to a temporary bypass storage, blasting said workpiece While being tumbled with a jet of blast media to remove residual core material while conveying 4the debris and spent blast media in sequence to said first and second separators while closing the intake to said bypass storage, and finally surface-cleaning and finishing said workpiece by subjecting it to the operation of the same fblast machine while slowly recycling back to the separators the temporarily stored debris which are previously segregated from the process system.

2. A machine for sequentially rough cleaning and knocking out lhard-to-dislodge debris `from workpieces and then finish-cleaning the same, said machine comprising, a workpiece receiving device adapted to turn the workpiece, a blast device arranged to throw blast media at the workpiece as it is turned, a lfeed device yfor delivering blast media to said blast device, a rst separator receiving debris and spent media falling away from said workpiece, said separator having a debris discharge and a preferred material discharge separate therefrom, said preferred material discharge normally delivering to a second separator, a bypass conveying overload material from said second separator intake to a temporary storage bin, a first valve controlling passage through said bypass, a second valve controlling discharge from said storage bin to said first separator, whereby said machine is sequentially controllable so as to initially block passage of material from said storage into said separator system while circulating ymaterial fall-ing away yfrom said workpiece through said separators and subsequently recycling the stored material and the reusable blast media through said separators and said blast device against said workpiece.

3. A method `for sequentially rough cleaning and then finish-cleaning workpieces, which method comprises placing a workpiece on -a support arranged to tumble said workpiece for shaking off a first surge load of debris material while delivering the debris to a first separator, transporting the overload ymaterial from `said first separator to a second separat-or while at the same time diverting a portion of the overload material to a temporary bypass storage, blasting said workpiece while being tumbled with a jet of blast media to remove residual debris material while continuing to convey the debris and spent blast media in sequence to said rst and second separators while closing the intake to said bypass storage las said second separator catches up to its loading, and finally surface-cleaning and finishing said workpiece by subjecting it to the operation of the same blast machine while slowly recycling back to the -separators the temporarily stored debris which was previously segregated from the process system.

4. A machine for sequentially rough cleaning and then finish-cleaning workpieces, said machine comprising, a workpiece receiving device `adapted to turn the workpiece, a blast device arranged to throw blast media at the workpiece as it is turned, a feed device for delivering blast lmedia to said blast device, a first separator rece-iving debris and spent media vfalling away from said workpiece, said separator having a debris discharge and -a preferred Inaterial discharge separate therefrom, a second separator arranged to receive the preferred material dischange from said first separator, a bypass for conveying material tending to overload said second separator to a temporary storage bin, a rst valve controlling passage through said bypass, a second valve controlling discharge from said storage bin back to said first separator, whereby said machine is controllable so as to initially block passage of material from said storage into -said separator system wh-ile circulating material fall-ing away from said workpiece through said separators and to subsequently recycle the stored material and the reusable blast media through said separators for reuse of said blast media by said blast device against said workpiece.

5. A machine for sequentially rough cleaning and knocking out hard-to-dislodge debris yfrom workpieces and then finish-clean-ing the same, said machine comprising, a workpiece receiving device adapted to tumble the workpiece, la blast device arranged to throw blast media at the workpiece as =it is tumbled, a feed device for delivering blast media to said blast device, a first elevator receiving a debris and spent blast media mixture from said blast device, la first separator receiving said mixture Ifrom said first elevator, said separator hav-ing la debris discharge and a preferred material discharge separate therefrom, a second elevator receiving said preferred material discharge, a second separator `arranged to receive the discharge of said second elevator, a bypass :convey-ing material tending to overload said second separator to a temporary storage bin, a first valve control-ling passage through said bypass, a second valve controlling discharge from said storage bin to said first elevator, whereby said machine is controllable so as to initially block passage of material from said storage bin to said first separator while circulating material falling away from said workpiece through said separators and for subsequently recycling the stored material through both `of said separators and the reusable blast media therefrom to said blast device from thence against said workpiece.

6. A machine for sequentially rough cleaning and knocking out hard-to-dislodrge debris from workpieces and then iinish-cleaning the same, said machine comprising, a Workpiece receiving device adapted to turn the workpiece, a blast device arranged to throw blast media at the Workpiece as it is turned, va feed device for delivering blast kmedia to `said blast device, an elevator receiving the blast media and debris discharge mixture from said blast device, a iirst separator receiving said mixture from said elevator, said separator having a debris discharge and a preferred material discharge separate therefrom, said preferred material discharge normally delivering to a second separator, a bypass conveying overload .material from said second separator intake to a temporary storage bin, a first valve controliing discharge from said storage bin to said elevator, |whereby said machine is controllable so as to initia-lly block passage of material -from said storage -into said separator system while circulating Imaterial falling away from said `workpiece through said separators and `for subsequently recycling the stored material through said separators and returning the reusable blast media to said blast device.

References Cited in the file of this patent 

2. A MACHINE FOR SEQUENTIALLY ROUGH CLEANING AND KNOCKING OUT HARD-TO-DISLODGE DEBRIS FROM WORKPIECES AND THEN FINISH-CLEANING THE SAME, SAID MACHINE COMPRISING, A WORKPIECE RECEIVING DEVICE ADAPTED TO TURN THE WORKPIECE, A BLAST DEVICE ARRANGED TO THROW BLAST MEDIA AT THE WORKPIECE AS IT IS TURNED, A FEED DEVICE FOR DELIVERING BLAST MEDIA TO SAID DEVICE, A FIRST SEPARATOR RECEIVING DEBRIS AND SPENT MEDIA FALLING AWAY FROM SAID WORKPIECE, SAID SEPARATOR HAVING A DEBRIS DISCHARGE AND A PREFFERED MATERIAL DISCHARGE SEPARATE THEREFROM, SAID PREFFERED MATERIAL DISCHARGE NORMALLY DELIVERING TO A SECOND SEPARATOR, A BYPASS CONVEYING OVERLOAD MATERIAL FROM SAID SECOND SEPARATOR INTAKE TO A TEMPORARY STORAGE BIN, A FIRST VALVE CONTROLLING PASSAGE THROUGH SAID BYPASS,A SECOND VALVE CONTROLLING DISCHARGE FROM SAID STORAGE BIN TO SAID FIRST SEPARATOR, WHEREBY SAID MACHINE IS SEQUENTIALLY CONTROLLABLE SO AS TO INTIALLY BLOCK PASSAGE OF MATERIAL FROM SAID STORAGE INTO SAID SEPARATOR SYSTEM WHILE CIRCULATING MATERIAL FALLING FROM SAID WORKPIECE THROUGH SAID SEPARATORS AND SUBSEQUENTLY RECYCLING THE STORED MATERIAL AND THE REUSABLE BLAST MEDIA THROUGH SAID SEPARATORS AND SAID BLAST DEVICE AGAINST SAID WORKPIECE. 